Monday, September 13, 2010

Some Recent Science Articles

String theory and black holes show a possible path to practical superconductors. "They figured out there was another system that shared the same properties as these superconducting strange metals, and best of all this system could be explained using gravitational mechanics and relativity instead of quantum mechanics. That system is a black hole. At low energy levels, the black hole model is a good match for the traits and behaviors that cuprates exhibit. Most importantly, electrical resistance in a black hole is directly proportional to temperature, not the temperature squared, which is the crucial match for superconducting cuprates. None of these revelations would be particularly useful if it wasn't possible to correlate the features of the black hole model with those of the strange metals, and that's a tricky task because black holes are described by relativistic features while the cuprates are governed by quantum mechanics. String theory solves that problem, providing a bridge between quantum and gravitational mechanics called gauge/gravity duality."

Scientists Say They Can Now Test String Theory "Duff and his colleagues realized that the mathematical description of the pattern of entanglement between three qubits resembles the mathematical description, in string theory, of a particular class of black holes. Thus, by combining their knowledge of two of the strangest phenomena in the universe, black holes and quantum entanglement, they realized they could use string theory to produce a prediction that could be tested. Using the string theory mathematics that describes black holes, they predicted the pattern of entanglement that will occur when four qubits are entangled with one another. (The answer to this problem has not been calculated before.) Although it is technically difficult to do, the pattern of entanglement between four entangled qubits could be measured in the laboratory and the accuracy of this prediction tested."

Working Tractor Beam Can Move Objects 5 Feet With Just Light " Using only light, Australian researchers say they are able to move small particles almost five feet through the air. It's more than 100 times the distance achieved by existing optical 'tweezers,' the researchers say. Not quite a simple grabby tractor beam, the new system works by shining a hollow laser beam at an object and taking advantage of air-temperature differences to move it around."

Here's an explanation of how scientists cool off atoms by shooting lasers at them.

On the really more theoretical scale, Physicists investigate fate of five-dimensional black strings, "While black holes in four-dimensional space-time are stable and can persist for a long time, their higher-dimensional analogues are usually unstable. One such theoretical analogue is a five-dimensional black string, which is unstable to perturbations and tends to decay into different forms. But like all unstable "black objects," it's difficult to determine what the end state of the perturbed system might be. Using a new computer code, physicists have been able to simulate the evolution of five-dimensional black strings well beyond earlier studies, leading them to predict that the strings eventually turn into five-dimensional black holes."

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